[electroman5000]

Hello to everyone!
Seeking the wisdom of the forum and suggestions. About half-year ago started to notice that a strange behaviour in engine work while on idle. Here are the list of simptoms which started at about 60k miles:

 - only happens when the engine is fully at operational temperature (never on cold or below 90 degrees C)
 - car starts without any issues, always, in hot or cold weather. (it was -12 here in UK for a bit, no issues)
 - revs gauge shows a slight dip and jump on idle (sometimes from 500 - 900 rpm)
 - increased vibration from engine (feels inside the car)
 - "wrong sound" of idling diesel engine
 - feels like a misfire, irregular work of engine
 - whilst driving the car behaves without any issues, engine pulls like a dream!
 - no smoke visible (DPF fitted), no abnormal smells
 - can happen any time, without any logical trigger  - can be absolutely normal for a month, but can be happening many times per day, or several times a week

 As far as I was reading some other forums in search for the answer I've came with a few guesses : crankshaft position sensor or/and fuel rail pressure sensor going nuts; several different issues with high pressure fuel pump, which could range (in repairs cost) from £50 to £500.

Has anyone else experienced similar issues? What are the solutions to it? 
The car still has got manufacturers warranty till February 2019, I am planning to go Hyundai with this issue soon. But like I said it can come up at any time or it can lay dormant for weeks not showing any signs. And HY charge £95 per hour for investigation.

The patient is serviced reguarly (last was at HY, 60k miles major service, all filters changed, then extra oil change at 67k miles), had undergone an engine carbon clean at about 55k miles. Had 3 bottles of Wynn's diesel fuel system and injector cleaner fluid since then. 
2014 1.6 CRDi 128hp, 73k miles

Here's a link Hyundai i30 1.6 CRDi 128hp rough intermittent idle - YouTube  of the problem (mostly it can be heard, camera doesn't capture the irregular vibrations that good):
Cheers!

[CraigB]

If everything is running fine and only noticeable at idle then maybe it's just the thermo fan cutting in

[eye30]

Have you considered/altering idle rpm's and see how it goes.

Re charge
As still under warranty get it back to dealers to check out.

Should be nil cost plus once it is logged then it is recorded on the system until resolved.

Sent from my ATU-L11 using Tapatalk

[nzenigma]

Another suggestion only, one injector is misbehaving. At higher Revs the effect of the inefficient one is smoothed by the other 3

[electroman5000]

If everything is running fine and only noticeable at idle then maybe it's just the thermo fan cutting in

Hm...Thermo fan? I believe that could cause a dip in revs once (like after switching on AC or rear demister,or lights), but should return to normal idle after. Looks like it's a task for HY to find out what demon possessed the engine.

[electroman5000]

Have you considered/altering idle rpm's and see how it goes.

Re charge
As still under warranty get it back to dealers to check out.

Should be nil cost plus once it is logged then it is recorded on the system until resolved.

Sent from my ATU-L11 using Tapatalk

Ehm...not really sure what do you mean by altering the idle rpm. You mean just revving up a bit while in neutral? Or...?
Yeap, going to HY soon. Let them sort it out, although it's one of those things where they'll take the car for a spin around the block and the engine will behave as normal. And as soon as I get it back it'll start playing up again...Maybe the video will convince them to investigate until they actually find the cause?

[electroman5000]

Another suggestion only, one injector is misbehaving. At higher Revs the effect of the inefficient one is smoothed by the other 3

That was on my mind. Still, logically thinking it should be playing up on idle all the time, and not just when it's in a bad mood, or why the hell it's doing it anyway.
Still, a possibility. I'm guessing HY should send the faulty injector for a refurb (if that's the fault), or replace with a new one.
A proper injector test will definitely show if there's an issue, but I doubt that HY will be willing to take off all 4 injectors, send them for a specialised test.
I believe that GD model CRDi engines have got Bosch injectors fitted. And one place I've found in my city charge £25 per injector.

Hyundai i30 Diesel Fuel Injectors

[nzenigma]

You are correct, switch of A/c and the like done with the cooperation of the ECU which will alter RPM to compensate.

"Have you considered/altering idle rpm's"?...... that's simple just twist the screw thingy on the carburettor.
 
Eventually, the alleged intermittent injector would probably fault permanently. If I were there I would be checking electrical connections especially to the injectors, look for corrosion  and use WD40.
The Common rail system on all the i30s is Bosch . For optimum performance the ECU should be remapped to the codes on each injector.
Hy are going to screw you, so I would look for an independent mechanic who has a few years in the trade, to advise you. Remember we are all just guessing at this stage. 

[diesel1984]

If this is the problem with injector probably there will be be a fault shown with too early dpf regenerations as result of black or white smoke. Probably every few days. On my opinion nothing without reading live data parameters.

[electroman5000]

diesel1984 - thanks for the thought. I think it's also linked somehow with the DPF regeneration.
However, I've been to HY dealer last week, told about the problem, showed video proof as well, and got a service booked for 12th of October. Was told that HY are going to look deeply in this matter, as apparently nobody from that dealership ever encountered such issue.

Update will follow after 12th of October. 

Cheers!

[electroman5000]

So....it all turned out quite well. Been at the HY dealer yesterday, got the car back. They said that the issue is now fixed and it was because of the software. They've updated it, and it all should be sound now. I hope it will be. Didn't charge anything too (job was done under warranty), which is always nice.
Will give some feedback after a month or so. Will see if the issue repeats, or dealer's magic touch on the ECU did the trick.

Good luck to everyone!

[CraigB]

Quite strange to get an ECU update on a four year old vehicle I'm glad it's running better for you though

[Dazzler]

So....it all turned out quite well. Been at the HY dealer yesterday, got the car back. They said that the issue is now fixed and it was because of the software. They've updated it, and it all should be sound now. I hope it will be. Didn't charge anything too (job was done under warranty), which is always nice.
Will give some feedback after a month or so. Will see if the issue repeats, or dealer's magic touch on the ECU did the trick.

Good luck to everyone!

Thanks so much for coming back to us. Fingers and toes crossed it's sorted. 

[electroman5000]

And here we are again, the engine started to play up on idle yesterday, and was doing it several times today while driving around for shopping. Guess software update didn't help that much at after all. Back to dealer in 3 weeks now, as will have to take a hire car, while they have a look at another issue.

[Dazzler]

And here we are again, the engine started to play up on idle yesterday, and was doing it several times today while driving around for shopping. Guess software update didn't help that much at after all. Back to dealer in 3 weeks now, as will have to take a hire car, while they have a look at another issue.

Bugger! Maybe that shark should be frowning now! 

[nzenigma]

And here we are again, the engine started to play up on idle yesterday, and was doing it several times today while driving around for shopping. Guess software update didn't help that much at after all. Back to dealer in 3 weeks now, as will have to take a hire car, while they have a look at another issue.

This is an intermittent idle and 'at moderate speed' misfire. I come back to my notion of one dodgy injector.

Good luck

[electroman5000]

Hello everyone. So I'm back from the HY dealer. This time they......"dramatic drum solo".......plugged in diagnostics machine and cleared the fault codes. http://rs253.pbsrc.com/albums/hh49/decbzr/badum-tishcom_5e1f7bf07da81488652e6a362cefafad_zps18d08f02.jpg~c200
After that done a road test and no fault codes appeared, so it's all fixed now! - anyway, that's what I've been told...When I asked how that is going to help ,the lady just smiled and said to monitor the issue and report if it comes back... Eh, I wish you could actually talk to the actual people in the service, that do the work on the car, and not just to those behind the desk.
Yeap. Just made me smile , and that's about it. At least got the car washed, and HY also repaired the squeaking drivers seat problem, free of charge. I feared it'd cost me around £150 in total (10 for courtesy car, 95+VAT for investigation, and few extra for additional work). Turned out lucky this time.

The issue has gone into some remittance lately, only happened 2 times in 3 weeks. Probably because I'm mostly on the motorway now (56 miles return trip to work).

So will keep you guys updated if the issues comes back.

Good luck everyone!

[nzenigma]

 
You are as skeptical as I am. 
Clearing codes................................... 
A. what were the codes?
B. What fault(s) did the codes indicate?
Do they understand the A+B relationship? 

Like you we await next episode. Thanks for keeping us in the loop.

[electroman5000]

You are as skeptical as I am. 
Clearing codes................................... 
A. what were the codes?
B. What fault(s) did the codes indicate?
Do they understand the A+B relationship? 

Like you we await next episode. Thanks for keeping us in the loop.

I know, it's a joke!
"Leave a note for wife to buy some bread. She throws the note away. No note - no problem!"

Will post any updates  on the story.

Cheers!

[electroman5000]

Hello to everyone!

So it's been 2 weeks now, and I only noticed an increased vibration once, without revs jumping up and down. Can't say it's a bad outcome, but the issue is still there (what a surprise!!!). Going for a long trip for the weekend, will see if it's going to be funny again.

And also noticed another problem now - Handbrake warning light not shown. - maybe someone can advise.

Cheers!

[Dazzler]

Hello to everyone!

So it's been 2 weeks now, and I only noticed an increased vibration once, without revs jumping up and down. Can't say it's a bad outcome, but the issue is still there (what a surprise!!!). Going for a long trip for the weekend, will see if it's going to be funny again.

And also noticed another problem now - Handbrake warning light not shown. - maybe someone can advise.

Cheers!

Cheers for that! 

[Vitruvian]

Hi, I had similar problem with bouncing revs and vibrations on my 1.6 crdi from time to time. (I was mentioned this on other discussion here on forum)

I resolve (hope so) this by fill full tank with some premium fuel and add diesel system cleaner aditive, since then I didn't experience this again, also I can feel engine is now smoother on idle.

I saw in my service history that they in Hyundai also puts diesel system cleaner aditive on every service, so maybe there is a good reason.

If you want you can try it too.

[electroman5000]

Hi, and thanks for advice. I do put about every 10th tank full of premium fuel. And I add diesel fuel system cleaner and cetane booster additives with every fuel up since I've had the car. First was using Millers Oils  diesel power ecomax, later switched on to HYDRA DIESEL POWER BLAST INJECTOR CLEANER and NBS LAKI Diesel Additive Cetane Booster. Mix them two together 2:1 and add 1 ml of solution per 1l of diesel with every fuel up.

Have to say that I've just returned from about 420 mile return trip, and engine was running fine, no funny business on idle. Will observe it's work and post if it anything goes wrong.

Cheers!

Hi, I had similar problem with bouncing revs and vibrations on my 1.6 crdi from time to time. (I was mentioned this on other discussion here on forum)

I resolve (hope so) this by fill full tank with some premium fuel and add diesel system cleaner aditive, since then I didn't experience this again, also I can feel engine is now smoother on idle.

I saw in my service history that they in Hyundai also puts diesel system cleaner aditive on every service, so maybe there is a good reason.

If you want you can try it too.

[CraigB]

Doesn’t the premium diesel have a higher cetane rating anyway it would contain cleaning additives or more of than standard diesel so using the premium diesel would probably be the better option to use all the time which would be easier and more cost effective than adding all the extra aftermarket additives.

[electroman5000]

Doesn’t the premium diesel have a higher cetane rating anyway it would contain cleaning additives or more of than standard diesel so using the premium diesel would probably be the better option to use all the time which would be easier and more cost effective than adding all the extra aftermarket additives.

It would be easier to use just premium diesel, but in the long run it's cheaper to buy standard diesel + additives. I've got myself 5l of both cleaning additives and cetane booster, so it will last for 10000 litres of diesel, while it cost me about £100. Over the course of those 10000 litres I'll save roughly £1500-£1800 ,comparing to fueling up with a premium diesel. 

[Dazzler]

Doesn’t the premium diesel have a higher cetane rating anyway it would contain cleaning additives or more of than standard diesel so using the premium diesel would probably be the better option to use all the time which would be easier and more cost effective than adding all the extra aftermarket additives.

It would be easier to use just premium diesel, but in the long run it's cheaper to buy standard diesel + additives. I've got myself 5l of both cleaning additives and cetane booster, so it will last for 10000 litres of diesel, while it cost me about £100. Over the course of those 10000 litres I'll save roughly £1500-£1800 ,comparing to fueling up with a premium diesel. 

That's interesting. I think most places over here only stock "Premium" diesel now so there is no cost penalty. Although I haven't owned a diesel since 2010.